The properties of diamond-bearing materials, obtained with the use of explosion energy, and also the conditions of their synthesis and separation from impurities are known in the art.
A paper (G. A. Adadurov et al, "The physics of Pulse Pressures" pp 44 (74), 1979, No. 4, Papers of All-Union Science-Research Institute of Physical and Radio Engineering Measurements, p. 157) discloses the characteristics of the product obtained in detonation of a mixture of RDX with a carbon material (black or graphite) in a blasting chamber in inert atmosphere. The purified product is a powder with the average particle size 0.05 to 5.0 mom, the average particle size calculated for the unit surface values is 0.04 to 0.08 mcm. The unit surface area is 20 to 42 m.sup.2 /g. The pycnometric density is 3.20 to 3.40 g/cm.sup.3. By the phase composition, the product is a mixture of diamond of a cubic (the lattice parameter a=0.357 nm) and a hexagonal modification (lonsdalite). The size of the coherent scattering region (CSR) of crystallites (i.e. the linear distance between the adjacent defects) is 10 to 12 nm, and the value of microdistortions of the second kind, characterizing the presence of defects, is within the limits 1 to 2.multidot.10.sup.-3. After anealing at 1073 K, the size of CSR was 12 nm, and the value of microdistortions of the second kind was reduced to 0.35.multidot.10.sup.-3. The temperature of the beginning of graphitization is over 1073K. About one fourth of the surface is occupied by carboxyl groups. When heated in vacuum, specimens lose some. 8% of the mass owing to liberation of oxygen, carbon monoxide and carbon dioxide molecules.
The properties of the diamond obtained from the carbon of explosives are described by K. V. Volkov with co-authors (The Physics of Compustion and Explosion, v. 26, No. 3, p, 123, 1990). Synthesis is effected when charges are set off in a blasting chamber in the atmosphere of carbon dioxide and in a water jacket. The particle size of the obtained diamond is 0.3 to 0.06 nm, the CSR size is 4 to 6 nm, the particle shape is round. The pyonometric density is 3.2 g/cm.sup.3. The product contains about 90% diamond, the balance, adsorbed gases. The product start oxidizing at 623 K. After fivehour holding at. 1173K, the degree of graphitization of the diamond is 10%.
Other versions of the method (A. M. Staver et al, The Physics of Combusion and Explosion, V. 20, No. 5, p. 100, 1984 and G. I. Savvakin et al, Proceedings of the USSR Academy of Sciences, V. 282, No. 5, 1985) are based of other or the same explosives in various kinds of atmospheres. The products resulting in this case feature properties similar to those described by K. V. Vollcov with co-authors.
For isolating the end diamond-bearing product, use is made of a complex of chemical operations directed at either dissolving or gasifying the impurities present in the material. The impurities, as a rule, are of the two kinds: non-carbon (metal, oxides, salts, etc.) and nondiamond forms of carbon (graphite, black, amorphous carbon).
The diamond-bearing material most close by the technical properties to the material of the present invention is that disclosed in British Patent No. 1154633.
According to this reference, the material is obtained by impact reduction of graphite. The resulting primary product of the synthesis contains, as a rule, less than 15% diamond of the total amount of carbon and a considerable quantity or inorganic impurities.
The purified diamond-bearing material consists of individual diamond particles having the average diameter no more than 0.1 mkm, the unit surface area from 40 to 400 m.sup.2 /g, hydroxyl, carboxyl and carbonyl groups comprise from 10 to 30% of the surface area. The diamond particles feature no external crystalline cut. Individual diamond crystallites;
feature wide spread over the diameter: 7 10.sup.-4 to 1 10.sup.-2 mcm (7 to 100 A). The material contains 87 to 92% by mass carbon, in addition it contains 0.1 to 2.0% hydrogen, 0.1 to 2.5% nitrogen and up to 10% oxygen.
When heating from 1123 to 1273 K for four hours in an inert atmosphere, the material loses no more than 5% of the mass in the form of carbon monoxide, carbon dioxide, water and hydrogen. From the results of radiographic analysis, the material contains only carbon, possible impurities of graphite do not exceed 0.2%, inorganic impurities neither exceed 0.2%.
The diamond-bearing material features abrasive and specific adsorption properties, which made it possible to surmise its application in polishing hard materials, strengthening metal coatings, and also in chromatography.
Thus, the references disclosing the know diamond-bearing materials synthesized with the use of the energy of explosion decomposition of explosives and also the specific processes for obtaining these materials fail to disclose the technical solutions to the problem which would make the basis for the effective, economically efficient and ecologically safe technology of industrial production of a diamond-bearing material with the present combination of properties.